Hexachlorobicycloheptenyl aromatic acids and derivatives thereof



United States Patent fiflce 3,3l8fi33 HEXACHLORQBHCYCLOHEPTENYL ARUMATHCAClD AND DERTVATWES THEREGF Emil F. Jason and Eliis K. Fields, Chicago,lill., assignors to Standard Oi! Company, Chicago, ill., a corporationof Indiana No Drawing. Filed July 1 3, 19-52, Ser. No. 209,747

Claims. (Cl. 260-434) This is a continuation-in-part of our copendingapplication Serial No. 795,891, filed February 27, 1959, now abandoned.

This invention relates to a novel group of halogencontaining aromaticorganic compounds. t especially relates to novelhexachlorobicycloheptenyl-substituted aromatic acids and derivativesthereof, and to their utilization in the preparation of insecticidal,herbicidal and fungicidal compositions; improved resinous compositionsand lubricants.

Specifically, this invention provides novel and useful monoand di-cyclicaromatic acids having one ring carbon atom joined to ahexachlorobicycloheptenyl radical. The invention further provides usefuland valuable derivatives of these acids including the anhydrides, acidhalides, esters, salts, amides and polyamides thereof. The inventionstill further provides useful compositions containing these novelaromatic acids and derivatives.

The novel acids of the present invention are monoor polybasic aromaticacids Which may be represented by the following structural formula:

wherein R is selected from the group consisting of H and low molecularWeight alkyl radicals, Z is an aromatic nucleus having less than threearomatic rings, such as a benzene, biphenyl or a naphthalene nucleus,and n is an integer from 1 to 4, usually 1 to 3, inclusive, and y is aninteger from 1 to 2, inclusive, corresponding to the number of aromaticrings in Z. Strictly speaking, the expression bicycloheptenyl radicalshould refer to the structural formula depicted above wherein R ishydrogen, but for simplicity, the expression will be employed in thespecification and claims to denote the radical attached to the ringcarbon atom of the aromatic acid wherein R is either hydrogen or a lowmolecular Weight alkyl radical having 1 to 4 carbon atoms, generally amethyl or ethyl radical. It Will be clear from the structural formulathat these novel compositions are derivatives of hexachloronorbornene.

The present invention provides the hexachlorobicycloheptenyl aromaticacids and their derivatives including their anhydrides, acid halides,esters, salts, amides, and polyamides. The novel compounds, especiallythe free acids and salts thereof are particularly useful in thepreparation of insecticidal, herbicidal, and fungicidal compositions.They exhibit high toxic action against many common insects.

The derivatives of the novel hexachlorobicycloheptenyl substitutedaromatic acids, especially the esters and amides, are useful asplasticizers for organic resinous compositions such as vinyl chloride,and vinylidene chloride polymers and copolymers. In addition to theirability to improve the flexibility and pliability of these compositions,they present the added advantage of contributing increased fireresistance and resistance to attack by fungi to the plasticized articlebecause of their high chlorine content. Dibasic acids and esters thereofare especially Patented May 9, 1&6?

valuable for the preparation of linear polyesters and/ or as componentsof alkyd resins. Esters of these acids with unsaturated alcohols may bepolymerized to produce products having excellent fungicidal andflame-resistant properties.

As indicated, the novel acids of the invention comprise the aromaticacids Which have one ring carbon atom attached to ahexachlorobicycloheptenyl radical. The novel acids can be monocarboxylicor poly-carboxylic and the aromatic nucleus can consist of a benzene,biphenyl or a naphthalene nucleus. The aromatic nucleus may be furthersubstituted, if desired, With other substituents, including alkylgroups, particularly those alkyl groups which are relatively resistantto oxidation, such as a tertiary butyl group, nitro-groups, additionalhalogen atoms, especially chlorine atoms, which further increase theactivity of the compounds in insecticidal and flame retardantproperties, and the like.

The hexachlorobicycloheptenyl substituted aromatic acids of the presentinvention can be prepared by any suitable method. They are preferablyprepared by condensing hexachlorocyclopentadiene with a monoor polyalkylsubstituted styrene or an alpha-alkyl, such as alpha-methyl, styrenecompound by the Diels-Alder reaction. The resultant condensate can thenbe oxidized preferably in the liquid phase and in the presence ofmetallic oxidation catalysts to convert one or more of the alkylsubstituents on the aromatic nucleus to carboxylic acid functionalgroups. We prefer to conduct the oxidation in the presence of a lowercarboxylic acid solvent and in the presence of a catalyst comprising inconjoint presence bromine and a heavy metal oxidation catalyst,especially Where it is desired to convert more than one alkyl group onthe aromatic ring to carboxylic acid groups.

Alternatively, hexachlorocyclopentadiene can be condensed with styreneor alpha-methyl styrene (or the corresponding ring-methyl derivativesthereof) and the Diels- Alder adduct subsequently alkylated to introduceadditional alkyl groups on the aromatic ring. These alkylated productscan, as hereinabove described, be smoothly oxidized to the aromaticmonoor polycarboxylic acids of the present invention.

Para-phenyl styrene or ethylene naphthalene, optionally additionallysubstituted With alkyl groups, may be substituted for the styrene in theforegoing reactions in the preparation of the biphenyl or naphthyldi-cyclic aromatic acids.

In preparing the novel compounds of our invention,hexachlorocyciopentadiene is first reacted with one of theabove-mentioned ethylene-phenyl or ethylene naphthyl-type feedstocks, orwith ring alkylated derivatives of such feedstoclcs. The Diels-Alderadducts are conveniently formed by heating equimolar quantities of thehexachlorocyclopentadiene and the aromatic feedstock, but a molar excessof either component can be employed. Generally molar ratios in the rangeof 0.5 to 1.5 are preferred. The reaction is effected at temperatures of50 C. to 200 C. and adduct formation is generally complete in 1 to 4hours. The adduct can be conveniently recovered by fractionaldistillation at reduced pressure.

When desired (or necessary as in the case of thehexachlorocyclopentadiene adducts non-substituted or alphasubstitutedfeedstocks), additional alkyl substituents are introduced into thearomatic ring by Friedei-Crafts alkylation of the Diels-Alder adduct.These alkylations are conveniently carried out at about 0-l60 C., andatmospheric pressure, employing alkyl halides, preferably having from 1to 3 carbon atoms, and aluminum chloride. The alkyl halides preferablyhave from 1 to 4 carbon atoms per alkyl group, such as methyl,isopropyl, n-butyl,

and secondary butyl and tertiary butyl. It will be clear, however, thatalkylation may be effected by conventional techniques known to the art,for example by reaction with equivalent alkylating agents includinglower alcohols, olefins, ethers, acids, acid halides, and the like, andthat aternative acidreacting catalysts may be employed including Felch,SbCl BF3, Zncl HF, H2804, H3PO4, P and the like.

In employing aluminum chloride as the alkylating agent, theabove-described Diels-Alder adducts are preferably dissolved in asolvent and contacted with isopropyl chloride or equivalent alkylatingagent in the presence of 0.025 to 1% by weight of aluminum chloride.Reaction periods of l to about 24 hours at ordinary temperature andpressure can be employed, and the alkylated product recovered bydilution with ice water and distillation of the organic layer.Alternative methods of working up the desired reaction product will beapparent to those skilled in the art.

The hexachlorocyclopentadiene adducts prepared as above described andhaving one or more alkyl groups on the aromatic rings are converted tothe aromatic acids of the present invetnion by liquid phase oxidation inthe presence of heavy metal oxidation catalysts. While they may beoxidized in any convenient manner, for example, by the method describedin U.S. Patent No, 2,245,528 of Loder, we prefer to effect the oxidationin a lower aliphatic carboxylic acid solvent and in the presence of acatalyst comprising in conjoint presence bromine and a heavy metaloxidation catalyst. Where desirable, the extent of oxidation can becontrolled to effect conversion of only one of several oxidizable alkylsubstituents on the aromatic ring to a carboxylic acid group. The use ofbromine-heavy metal oxidation catalyst, as referred to in U.S. PatenflNo. 2,836,816 assigned to Mid-Century Corporation, permits theconversion in high yield of one or more such alkyl groups to carboxylicacid substituents.

Oxidation can be effected in lower aliphatic carboxylic acids as solventincluding acetic acid, propionic acid, butyric acid and the like.Mixtures of acids can be employed. As metal oxidation catalyst, heavymetals especially those having atomic numbers from 23 to 29 areemployed. Mixtures of metals can be used. Cobalt, manganese and mixturesthereof are especially effective. Surprisingly, we have found that thehexachlorobicycloheptene ring is remarkably stable to such oxidationprocedures, and the only groups that are oxidized are the alkylsubstituents on the aromatic ring.

The oxidation is conducted at atmospheric or superatmospheric pressure,generally at a pressure at least sufficient to maintain liquid phasereaction conditions. Preferably, temperatures of 100 C. to 250 C. areemployed and pressures conveniently of 200-400 p.s.i. when acetic acidis the solvent. The metal catalyst is employed in amounts of 0.01 toabout 1% based on the aromatic compound, preferably in the form oforganic or inorganic salts. Bromine as the free element, or in the formof organic or inorganic compounds capable of supplying bromine ion tothe reaction mixture, is employed in an amount between 0.1 and 10.0 gramatom per atom of metallic oxidation catalyst. The oxidizing gas maycomprise air, pure oxygen, or mixtures of oxygen and inert gas.

The novel hexachlorobicycloheptenyl substituted aromatic acids of ourinvention have outstanding insecticidal as well as herbicidal andfungicidal properties and can be employed in insecticidal, fungicidaland herbicidal sprays and dust compositions. They may be employed aloneor in combination with other known organic or inorganic insecticidaltoxicants and as such may be applied in the form of solutions in organicsolvents, as wateremulsions or dispersed on solid carriers such asdiatomaceous earth, bentonite, talc and the like.

The acids of our invention are valuable for the preparation of alkydtype resins, as components of lubricating oil compositions, asanti-corrosion agents and the like. They are valuable intermediates forthe production of many useful derivatives including the salts, esters,anhydrides, acid halides and amides. Heavy metal salts such as those oflead, iron, manganese and cobalt can be employed as fungi-resistantpaint driers. Copper and mercury salts can be used as fungicides, aswood preserving agents or as lubricating oil additives. Other usefulsalts of these novel acids can be employed as stabilizers for polyvinylchloride, as extreme pressure lubricants and as insecticides. The metalsalts may be prepared directly from the free acids, for instance, byheating an oxide, hydroxide or carbonate of the metal with the acid, orby double decomposition of an alkali metal salt of an acid with asoluble salt of the desired metal.

Esters having many unusual and beneficial properties may be preparedfrom the novel acids of our invention by esterifying them with saturatedmonoor dihydric alcohols, unsaturated alcohols, benzyl alcohols, orphenols, normally having not more than about 20 to 22 carbon atoms permolecule, although in some instances a higher number of carbon atoms maybe desired. Particularly valuable are the esters of the monoanddicarboxylic acids of the invention with lower saturated alkanols havingfrom 2 to 12 carbon atoms in the molecule, e.g., ethanol, sec. butanol,n-octanol, isooctyl alcohol, decyl alcohol, lauryl alcohol, stearylalcohol, and the like. These compounds have useful properties asplasticizers for synthetic resins such as vinyl halides, to which theyimpart valuable flameproofing and fungi-resistant properties.Dimethylesters of the dibasic acids of our invention are worthy ofmention as intermediates for the preparation of linear superpolyestersof the'Dacron-type, and may be used as the sole diester component or inadmixture with other aromatic dibasic acid diesters usually employed inthe preparation of such linear superpolyesters by reaction with dihydricalcohols.

A wide variety of other useful ester derivatives of the novel acids ofour invention can be prepared, including for example, esters of theseacids with unsaturated alcohols such as allyl alcohol, which esters canbe homoor co-polymerized with vinyl compounds by means of peroxide-typecatalysts. Other alkanols from which esters may be made are oleylalcohol and linalyl alcohol.

Other illustrative alcohols are cyclohexanol, benzyl alcohol, salicylalcohol, ethylene glycol, 1,4-butanediol and hexamethylene glycol.

Amides of the novel hexachlorobicycloheptenyl substituted aromatic acidsare of value as insecticides, fungicides or herbicides, or as additivesfor compositions having insecticidal or fungicidal activity. The amidesmay be employed as components of resinous compositions, as plasticizersor lubricants. They may be prepared by methods known in the art, forexample, by reaction of the :acid halides or anhydrides described hereinwith primary or secondary alkyl, aryl, alkaryl or heterocyclic amines,such as ethyl amine, isopropyl amine, decyl amine, allyl amine, aniline,substituted anilines, and the like, usually having not more than about20 or 22 carbon atoms, and preferably not more than 10 or 12 carbonatoms. Heterocyclic amines such as 2-aminopyridine, Z-aminothiazole,4-aminoquinoline and 3-furylamine may also be used.

Further details of our invention are set forth in the followingnon-limitative examples, which are provided for the purpose ofillustration only, and the invention is not to be regarded as limited toany of the specific conditions or reactants employed therein.

Example 1 The Diels-A-lder adduct of hexachlorocyclopentadiene andparaisopropyl-alpha-methylstyrene was prepared as follows: To a stirred40 ml. sample (0.25 mole) of hexachlorocyclopentadiene was slowly added40.2 g. (0.25 mole) of para-isopropyl-alpha-methylstyrene while thetemperature was maintained at -130 C. After addition was complete themixture was held at this temperature for 6 hours. Distillation of thereactor contents gave 41.7 g. (40% theory) of a pale yellow oil, boilingat l71-l75 C. at 0.3 mm. Hg pressure and identified as2-methyl-2-(4-isopropylphenyl) hexachloronorbornene, hoving a molecularweight of 415:12 (theory 432).

A portion of the adduct so prepared (35 g.) was dissolved in 150 g.glacial acetic acid to which was added 0.2 g. cobalt acetate, 0.4 g.manganese acetate and 0.5 g. ammonium bromide dissolved in 6 ml. ofwater. The solution was charged to a tubular reactor and heated to 400F. while air at 400 psi. was passed through the solution by means of asparge-r located below the liquid level. The reactor pressure wasmaintained by controlling the exit flow of gases. When oxygen absorptionceased (determined by analysis of the exit gases for oxygen) the reactorcontents were cooled, removed by flushing with water and acetone, anddiluted with a large volume of Water. The solids which precipitated weredissolved in anueous caustic, and recovered bv acid fication with HCl.The acid was obtained in 68% yield. It had a melting point of 202-205"C., was difficultly soluble in aqueous 10% sodium hydroxide solution,and was identified as 2 methyl-2-(4-carboxyphenyl)-hexachloronorbornene.Elemental analysis for C H Cl O.Calculated: carbon, 41.47; hydrogen2.29. Found: carbon 41.90; hydrogen 2.52.

Example 2 Similarly, 29.5 g. vinyltoluene was reacted with an equimolarquantity of hexachlorocyclopentadiene at 145 C. by dropwise addition ofthe styrene compound over a period of 2 hours. After heating for anadditional hour at 140-145 C., the reaction mixture was distilled togive a quantitative yield of the adduct boiling at 180- 185 C. at 0.8mm. Hg pressure and consisting of a mixture of the isomers2-(4-methylphenyl) and 2-(3-methylphenyl)-hexachloronorbornene. Therefractive index of the adduct was 11, 1.5857 and the molecular weight391 (theory 390).

A 50 g. sample of this adduct was oxidized in accordance with theprocedure of Example 1 to yield 70% of a monobasic acid, melting point225-230 C. identified as 2-(carboxyphenyl)-hexachloronorbornene.Elemental analysis for C T-1 G 0 .-Calculated: carbon, 40.0; hydrogen,1.91. Found: carbon, 39.7; hydrogen, 2 1

Para-tolyl styrene may be substituted for the vinyltoluene in order toobtain the Z-(carboxybiphenyl)-hexachloronorbornene, and a vinylnaphthalene substituted with one or more methyls at other than the alphaposition may be used to prepare 2-(carboxyn-aphthyl)-hexachloronorbornene.

Example 3 The example illustrates the preparation of an alkylatedhexachlorobicycloheptenyl substituted benzene by alkylation of apreviously prepared Diels-Alde-r adduct.

A mixture of 37.2 g. (0.1 mole) phenyl-hexachloronorbornene (adduct ofhexachlorocyclopentadiene and styrene), 100 ml. of carbon tetrachloride,and 2 g. of aluminum chloride was stirred at about 5 C. while 22.4 g.(0.3 mole) of isopropyl chloride in 50 ml. carbon tetrachloride wasadded dropwise over a period of hour. The mixture was allowed to warm toroom temperature and then stirred for an additional 16 hours. Thereaction mixture was poured into ice water, the organic layer separated,and the aqueous layer extracted twice with carbon tetrachloride. Theorganic extracts were combined, dried and distilled giving a p-ale.yellow oil boiling at 165-170 C., at 0.2 mm. Hg pressure and having arefractive index n 1.5700. This oil solidified on standing to a solidhaving a melting point of 163- 165 C. on recrystallization frommethanol. This solid was identified as the monoisopropyl derivative ofphenylhexachloronorbornene. The diisopropyl compound was isolated fromthe reaction mixture, and Was oxidized to the corresponding dibasic acidfollowing the procedure of Example 1. A yield of 70% of theory wasobtained of dibasic acid isomers having an acid number of 242 and M.W.of 474:14. Theoretical ac-id number and molecular weight for suchisomers are 241 and 464, respectively.

Example 4 The alkylation of methylphenyl-hexachloronorbornene(Diels-Alder adduct of hexachlorocyclopentadiene and vinyltoluene) waseifected in the following manner. A mixture of 507 g. (1.3 mole) of thehexachloronorbornene, 1000 ml. of carbon tetrachloride and 6 g. ofaluminum chloride was stirred at room temperature while 203 g. (1.59moles) isopropyl chloride in 200 ml. carbon tetrachloride was added.Addition was complete after 3-4 hours. The reaction mixture was stirredfor 24 hours until HCl gas evolution ceased. The alkylate was dilutedwith ice water and the organic material recovered and distilled. Theproduct was a pale yellow oil boiling at 175-180 at 0.3 mm. Hg pressureand having a refractive index of n 1.5664. An 88% yield was obtained.Analysis of the distillate showed 47.18% C and 3.80 H compared to 47.22C and 4.66 H calculated for the empirical formula C H Cl Oxidation ofthe alkylate so obtained by the procedure of Example 1 gave 70% yield ofa dibasic acid having a melting point of 226-230 C. and acid number of240, identified as hex chloro'bicycloheptenyl phthalic acid.

Example 5 The ethyl ester of the monobasic acid of Example 2 wasprepared by refluxing a mixture of 30 g. of the acid and 200 ml. ethanolin the presence of 2 ml. of concentrated sulfuric acid. After thereaction was complete, the mixture was distilled to produce ethylhexachlorobicycloheptenyl benzoate, a viscous yellow oil having aboiling point of 200-201 C. (0.2 mm.). The ester was obtained in 90%yield.

This compound as a 5% solution in refined oil was tested as aninsecticide and found to have toxic action against common housefiies.

Esters having releated properties are obtained by replacing the ethanolin the above-described process with each of the following alcohols:methanol, n-butanol, n-octanol, isoocytyl alcohol, n-onyl alcohol anddodecanol.

Example 6 The sodium salt of the acid of Example 2 was prepared byneutralization of a 10 gm. sample of the acid with 5% aqueous sodiumhydroxide, the sodium salt being recovered by evaporating the solutionto dryness. The salt was a white crystalline solid. The sodium salt wastested as an insecticide (5% solution in water) and found to have toxicaction against common housefiies.

The copper salt of the acid of Example 2 was prepared as follows: asaturated aqueous solution of the sodium salt prepared as above wasfiltered and the filtrate added to a clear solution of copper sulfate inwater. The copper salt which precipitated immediately was filtered offand dried. It was a light green crystalline solid. Compositionscontaining this salt have fungicidal activity.

Example 7 The acid chloride of the acid of Example 2 was prepared byrefiuxing parts of the acid with an excess of thionyl chloride forseveral hours. The mixture so obtained was chilled and the precipitatedacid chloride filtered on a Buchner funnel. The acid chloride obtainedin high yield had a melting point of -90" C. It was pale yellow or tanin color. Additional quantities of the acid chloride could be recoveredby distilling oif excess thionyl chloride from the filtrate.

The acid chloride so obtained was treated with excess concentratedammonium hydroxide to give the amide in essentially quantitative yield,having a melting point o ll3-l20 C. Elemental analysis of this compoundshowed 40.00% carbon and 2.32% hydrogen as compared to 40.09% carbon and2.14% hydrogen calculated for C14H9NOC15.

An alternative method of preparing an amide is to react the amine withthe acid halide, preferably the chloride, of anhexachlorobicycloheptenyl aromatic acid herein described in benzene orcarbon tetrachloride. Still another method is to dissolve the acid andamine in water to yield the ammonium salt, evaporate the solution todryness, and heat to about IOU-200 C. for several hours.

The preparation of an acid halide using thionyl chloride, describedabove, is particularly suited to preparing the acid chlorides andbromides. An alternative is to react the 'hexachlorobicycloheptenyl acidwith phosphorous or phosphoric chloride or bromide, to yield thecorresponding acid halide and phosphorous or phosphoric acid. To preparethe acid fluoride, the acid may be reacted by heating with a simplefluoride such as KP or AgF. To prepare the iodide, reaction of the acidmay be with NaI or Cu I Example 8 The dicarboxylic acid of Example 4 wasconverted to the acid chloride by the procedure described in Example 7.The acid chloride so obtained was dissolved in 100 ml. benzene and addedto a stirred solution of 3.7 gm. 1,6-hexanediamine and 3.0 gm. sodiumhydroxide in 50 ml. water. The polyamide was recovered from the benzenelayer by evaporation of the solvent on a steam bath. The product soobtained had a nitrogen content of 3.47% and chlorine content of 37.3%,and had a slightly milky color, just off water white. The polyamide didnot support combustion in air, even after having been initially ignitedin an open flame. Films prepared therefrom by casting from acetonesolution adhere tightly to tin-plated steel, and may be used alone orcompounded with known resinous materials for the preparation oftenacious, flameresistant metal surface coatings. structurally, thepolyamide obtained from hexanediamine may be represented by:

l Cl 0:0

ii it l 01001 I Cl :0

H Cl Example 9 The acid of Example 3 was tested as an extreme pressureadditive by incorporation in solvent-extracted SAH 30 lubricating oil. A2% solution of the acid in this oil carried a load of 24 pounds on theAlrnen machine, and failed at 26 pounds. In comparison, the base oilwithout the additive carried a load of 6 pounds but failed at 8 pounds.

It will, of course, be understood that the present invention or to theparticular compounds hereinabove described. The specific procedures can,of course, be varied Within the skill of the ordinary organic chemist.For example, various known techniques for carrying out Frie-- del-Craftstype alkylation reactions may be applied in the synthesis of thefeedstocks employed in the preparation of the acids and derivativesthereof which constitute our invention. The oxidation of alkyl aromatichexachloronorbornenes is not necessarily carried out with molecularoxygen-containing gas, as hereinabove illustrated, but may be conductedby means of known chemical oxidants such as chromic anhydride, potassiumpermanganate, nitric acid and the like according to methods known in theart to be applicable to the oxidation of alkyl substituents on anaromatic nucleus. Other methods for air oxidation, including the use ofhigher or lower temperatures, other metallic oxidation catalysts andvapor phase or non-solvent liquid phase oxidation conditions are equallyapplicable.

It is apparent that a wide variety of monoand polycarboxylic aromaticacids and their derivatives are provided by the present invention, andthe invention is not to be limited in any way by the particularoperating examples provided herein. The compositions of the presentinvention generally useful as pesticides, herbicides, fungicides andinsecticides, and can be employed as such either alone or together withinsecticidal adjuvants known to the art. The novel compositions of ourinvention are valuable as ingredients of dyes and pigments, additives(especially extreme pressure additives) for lubricating oils, ascomponents of various resinous compositions, e.g., alkyd resins,polyester resins, polyamide resins, and the like, as anti-corrosionagents, viscosity index improvers and the like.

Useful salts of the acids of our invention include those of the alkalimetals, such as sodium, potassium, rubidium, cesium; the alkaline earthmetals, such as barium, calcium, magnesium, strontium; and polyvalentmetals such as chromium, mercury, nickel, cobalt, manganese, nickel,tin, titanium, vanadium, zinc, cadmium, aluminum, zirconium, lead,molybdenum, iron, the precious metals, such as silver, platinum, or thelike, including the ammonium ion. Such salts may be variously employed[as paint driers, as stabilizers for polyvinyl chloride, as additivesfor improving the load carrying capacity of lubricating oils, etc.Copper and mercury salts are particularly valuable as fungicides andwood-preserving agents.

The metal salts may take a number of forms. For instance, they may be inthe form of mono-, dior trialkali metal salts, or in the form of adi-valent (as the tion is not limited to the particular methods ofpreparacupric or stannous) salt of two mono-carboxylic acids,

or of one di-carboxylic acid where the carboxyl groups are in the orthoposition, or in the form of:

Cl M f 01001 where M is a tri-valent metal ion, such as ferric, chromicor aluminum.

The intra-molecular and inter-molecular anhydrides of the acids may bemade by dehydrating by heating, respectively, a dior tri-carboxylic acidhaving carboxylic groups ortho to one another, or by heating togethermono or other polycarboxylic acids.

It will be apparent that our invention provides a novel class ofaromatic organic acids and their derivatives, including esters, salts,amides, polyamides, acid chlorides, anhydrides and the like, having Wideutility in many fields of application.

It is to be understood that in the specification and the claims, thephrase "hexachlorobicycloheptenyl refers to a radical having thestructure:

I C C12 01 I wherein R may be selected from the class consisting ofhydrogen and low molecular weight alkyl radicals of less than aboutcarbon atoms per radical. The phrase aromatic acids having less than 3aromatic rings refers to substituted and non-substituted benzene,biphenyl and naphthalene nuclei having at least one carboxyl groupattached to an aromatic ring carbon atom. The phrase metal salts alsoincludes ammonium.

Having thus described the invention, we claim:

ll. Hexachlorobicycloheptenyl aromatic carboxylic acids of the formula:

wherein R is selected from the class consisting of hydro gen and alkylradicals of less than about 5 carbon atoms and Z denotes a divalent arylradical containing less than 3 benzene rings and wherein x consists of acarboxyl group or the corresponding acid halides, amides, metal salts,and lower alkanol and olefinically unsaturated alkanol esters of saidcarboxylic acids and wherein n is an integer from 1 to 5 inclusive.

wherein Z denotes a divalent aryl radical containing less than 3 benzenerings and wherein n is an integer from 1 to 5 inclusive.

l@ 3. Hexachlorobicycloheptenyl aromatic acids of the formula:

carboxylic wherein n is an integer from 1 to 5 inclusive.

4. Aromatic carboxylic acids having the formula:

(COOH)n wherein n is an integer from 1 to 5 inclusive, and R is selectedfrom the class consisting of hydrogen and alkyl radicals of less thanabout 5 carbon atoms.

5. Hexachlorobicycloheptenyl phthalic acid of the formula:

01 mil 01c 01 01 l 6. Hexachlorobicycloheptenyl naphthoic acid of the 7.Hexachlorobicycloheptenyl aromatic acid esters of the formula:

carboxylic wherein 2 denotes a divalent aryl radical containing lessthan 3 benzene rings and where R is lower alkyl or lower alkenyl andwherein n is an integer from 1 to 5 inclusive.

8. The ethyl ester of Z-(carboxyphenyl)-hexachloronorbornene of theformula:

9. Amides of hexachlorobicycloheptenyl aromatic carboxylic acids of theformula of claim 1 wherein R is H.

10. Acid halides of hexachlorobicycloheptenyl aromatic carboxylic acidsof the formula:

01 (I) 01 z o-Y wherein Z denotes the divalent aryl radical containingless than 3 benzene rings and wherein y is a halogen and wherein n is aninteger from 1 to 5 inclusive.

11 11. The acid chloride of hexachlorobicycloheptenyl benzoic acid ofthe formula:

12. Metal salts of hexachlorobicycloheptenyl aromatic 10 carboxylicacids of the formula of claim 1 wherein R is H.

13. Cupric salts of hexachlorobicycloheptenyl benzoic acid of theformula:

C/\ M Q 20 14. Sodium salts of a hexachlorobicycloheptenyl ben- 15.Mercuric salts of a hexachlorohicycloheptenyl dicarboxylic acid of theformula:

@1001 C00 Hg 01 References Cited by the Examiner UNITED STATES PATENTSLinford et a1. 260-438 Kaplan et a1 260-434 Polen et a1. 260-648Newcomber et a1. 260-558 Keller et a1. 260-475 Patrick et a1. 260-475England 260-78 Kwolek et a1. 260-78 Abramo et a1. 260-558 Raecke et a1.260-515 Sauer 260-544 Feeman 260-544 Schenk 2-60-515,

Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,318,933 May 9, 1967 Emil F. Jason et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Columns 11 and 12, claims 13 and 15, after the formulas, eachoccurrence, insert wherein n is 2.; column 11, claim 14, after theformula insert wherein n is l.--.

Signed and sealed this 21st day of November 1967.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissionerof Patents

1. HEXACHLOROBICYCLOHEPTENYL AROMATIC CARBOXYLIC ACIDS OF THE FORMULA: